1. Field of Invention
This invention relates generally to filters for treating water. More specifically, this invention relates to a water filter that neutralizes harmful substances, such as chlorine and chloramines which is absorbed by the human body during contact or consumption.
2. Description of Related Art
As discussed in detail in U.S. Pat. No. 5,300,224, which issued Apr. 8, 1994 to Frederick A. Farley, chlorine is a very effective disinfectant and has been used in municipal water for nearly 100 years. The growing concerns about chlorine in water are the chlorination by products, “chlorinated hydrocarbons,” known as trihalomethanes (“THM”). Most THM's are formed in tap water when chlorine reacts with naturally occurring substances. Risks for certain types of cancer are now being correlated to the use of chlorinated water. Studies are now beginning to show that humans can consume large amounts of chlorine in the shower. These effects of chlorine may result from either ingestion or absorption through the skin. There is also evidence that shows that chlorine can destroy protein in our body and cause adverse effects on skin and hair. The presence of chlorine in water may also contribute to the formation of chloramines in water, which can cause taste and odor problems. Since chlorine is required by public health regulations to be present in all public tap water supplies, it is up to the individual to remove it at the point-of-use in the home.
Activated carbon filtration (“AC”) is effective in reducing certain organic chemicals and chlorine in cold water. Chlorine is attracted to and held (absorbed) onto the surface of the carbon particles. U.S. Pat. No. 4,107,046 discloses a filter cartridge for an internally by-passable water purifier apparatus. The apparatus includes valve means for directing water through the filter cartridge, which contains granulated carbon mixed with a silver zeolite, and may be sandwiched between fibrous sheets of material, such as felt, before it exits the apparatus. U.S. Pat. No. 4,172,796 discloses a water faucet having water purification or filtering means, made from activated carbon, or carbon with oligodynamic silver, formed therein. U.S. Pat. No. 4,504,389 discloses a water faucet having a separate housing containing a removable cartridge or filter element made from various stages of polyethylene and activated carbon particles therein. However, high water flow rate and high water temperature limits carbon's water filtration efficiency. The efficiency of absorption is quickly nullified when the water becomes warm. The lifetime of an activated carbon filter is very short. An activated carbon filter gets clogged very quickly by the dirt it is meant to stop. As soon as that happens, it immediately starts to release previously adsorbed contaminants back into the water stream.
Another type of filter media called KDF is disclosed in U.S. Pat. Nos. 4,642,192 and 5,122,274, which is an “electronegative cell potential type” chlorine filter media. The preferred media to filter out chlorine disclosed in these patents is comprised of a mixture of copper and zinc.
Two types of shower filters devices are disclosed in U.S. Pat. Nos. 5,152,464 and 5,300,224. The devices disclosed in these patents are compact filter assemblies containing a filtering media, such as copper and zinc, to filter out unwanted chlorine in water passing through the filters. However, copper and zinc media does not remove chloramines and, because its efficiency depends on water temperature, it does not work well in cold water. There are several other limitations using KDF as a de-chlorinating agent. KDF filters are also affected by water pressure. When the water pressure is not high enough, water simply cannot pass through the KDF powders. Another major problem of KDF filters is that the lifetime of the filter depends on the quality of the water passing through it. When the quality of the water is bad, the dirt a KDF filter removes from the water quickly covers the surface of the KDF that in turn makes the filter ineffective very quickly.
U.S. Pat. Nos. 5,914,043 and 6,056,875 disclose a method of filtering water utilizing separate beds of non-soluble ceramic-type calcium sulfite beads, made from a ceramic binder and calcium sulfite, and a copper-zinc media. Sulfur-based compounds, such as calcium sulfite or sodium sulfite (or sulfate), although are effective dechlorinating agents, can be toxic to both humans and animals. The addition of excess sulfite and sulfate chemicals to our water has always been a concern. There remains the need in the art for a safer and more environmentally conscious filter that provides the most efficient filtering of unwanted chlorine from water while at the same time meeting the more stringent health and safety regulations of local communities and governmental agencies such as the EPA.
Vitamin (ascorbic acid or sodium ascorbate) reacts rapidly and stoichiometrically with active chlorine and has limited interactions with disinfection byproducts. It fully neutralizes both chlorine and chloramines. There are several powerful arguments for using Vitamin instead of KDF, activated carbon, or sulfur-based compounds as dechlorination agents. Vitamin utilizes ascorbic acid chemistry for dechlorination. It is made with an essential vitamin for humans and many animals, which are known to boost the immune system, and improves the skin and hair condition of humans. It is also the safest and least toxic of dechlorination agents.